Commitments and Contingencies (Details 1) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2014 Claimant Claim	Dec. 31, 2013 Claimant
Respirator Mask/Asbestos Litigation
Loss contingencies
Accrued loss contingency reserve	$ 175,000,000	$ 175,000,000	$ 152,000,000
Insurance receivables	41,000,000	41,000,000	58,000,000
Total number of named claimants		2,230	2,200
Number of total claims settled and taken to trial		9
Number of total claims tried to verdict		8
Number of total claims settled and tried to verdict		7
Number of total claims dismissed		1
Increase in insurance liabilities	31,000,000	52,000,000
Payments for fees and settlements related to litigation	9,000,000	28,000,000
Respirator Mask/Asbestos Litigation - State of West Virginia
Loss contingencies
Amount of liability recorded for unspecified worker's compensation and healthcare benefits	0	0
Number of additional defendants		2
Respirator Mask/Asbestos litigation - Excluding Aearo Technologies
Loss contingencies
Accrued loss contingency reserve	151,000,000	151,000,000
Insurance Disclaimer Action
Loss contingencies
Proceeds received in connection with respirator mask/asbestos receivable	6,000,000	17,000,000
Number of insurers who filed a declaratory judgment action against the company		2
Number of the entity's insurers named in the action, low end of range		60
Respirator Mask/Asbestos Litigation - Aearo Technologies
Loss contingencies
Accrued loss contingency reserve	24,000,000	24,000,000
Quarterly fee paid to Cabot to retain responsibility and liability for products manufactured before July 11, 1995		100,000
Number of underlying claims concerning whether they were Cabot's responsibility		258
Outstanding issues remaining		2
Environmental Matters - Remediation
Loss contingencies
Accrued loss contingency reserve	26,000,000	26,000,000	27,000,000
Insurance receivables	11,000,000	11,000,000	11,000,000
Number of years remediation payments expected to be paid for applicable sites		20 years
Environmental Matters - Other
Loss contingencies
Accrued loss contingency reserve	44,000,000	44,000,000	48,000,000
Insurance receivables	15,000,000	15,000,000	15,000,000
Environmental Matters - Regulatory Activities
Loss contingencies
Number of PFCs the EPA has proposed to have public water suppliers monitor		6
Amount of PFOA in drinking water allowed per provisional health advisories in grams per liter		0.0000004
Amount of PFOS in drinking water allowed per provisional health advisories in grams per liter		0.0000002
Number of years after phase-out decision in May 2000 that the Company stopped manufacturing and using vast majority of perfluorooctanyl compounds		2 years
Environmental Matters - Regulatory Activities | Alabama
Loss contingencies
Wastewater treatment plant sludge containing PFCs surrounding Decatur facility pursuant to a permit		20 years
Environmental Matters - Litigation | Morgan County, Alabama
Loss contingencies
Total number of named claimants		3
Environmental Matters - Litigation | New Jersey
Loss contingencies
Lower end of range of number of companies served with a complaint		250
Number of additional defendants		5
Total cost of cleanup proposed by the EPA, of which the Company believes its applicable share, if any, is likely to be a fraction of one percent		$ 1,000,000,000
Total cost of cleanup proposed by EPA of which company believes its applicable share to be fraction of this maximum percentage (as a percent)		1.00%
Number of commercial drum conditioning facilities used		2
Environmental Matters - Litigation | Metropolitan Council, Minnesota
Loss contingencies
Number of wastewater treatment plants from which PFC-containing sludge and biosolids may allegedly be discharged by Metropolitan Council, low end of range		1
Environmental Matters - Other Environmental Litigation
Loss contingencies
Number of years remediation payments expected to be paid for applicable sites		4 years
Number of former disposal sites with PFC present in soil and groundwater in Washington County, Minnesota		2